Developments in civil aviation, as well as military are characterized by improved fuel economy, enhanced safety, lower harmful exhaust emissions and reduced noise. Specifically, in the military aviation sector, is also a move towards improved stealth characteristics, “Stealth—signature adaption”.
Proposed invention addresses these areas of improvement and can be applied on flying wings or aircraft of the type “blended wing body”, but also on conventional aircraft. The design is then integrated in the wings. The invention enables improved properties such as short take-off and landing distances (“STOL” Short Take-Off and Landing), lower fuel consumption, reduced noise, improved safety and specifically interesting in the military field; greatly improved stealth characteristics, primarily for radar and IR signatures. The invention allows for vectoring the thrust and can in advanced designs allow vertical takeoff and landing (“VTOL” Vertical Take-Off and Landing).
Previously known solutions known from the patents below shows the cross flow type fans. A fan rotor of a cross flow fan has no solid rotor hub that allows the air to pass through the hub, which is made clear, in for example FIG. 1 of U.S. Pat. No. 3,178,131 A. This design is not suitable for high speeds as the structure is too weak. Further, it is very sensitive to damage from foreign objects. A further significant difference between the device in U.S. Pat. No. 3,178,131 and the invention according to the application is that U.S. Pat. No. 3,178,131 discloses a system with elongated fan coils. Also U.S. Pat. Nos. 6,016,992, 3,082,976 and 3,065,928 shows a system with fan designs where fans are formed as elongated rollers, which are also open inside, so-called cross-flow fans. If b is the length of the roll, and D is the diameter of the roll, in which the measure D also includes the fan blades, then b>>D of the previously known solutions and according to the invention of the application b<=D. This difference is important as the invention according to the application requires air to pass through the fan, flow in axially and flow out radially. In the previously known solutions form-wisw almost similar to the invention, the air flows mainly radially into the fan as well as radially out from the fan. The previously known fans have no massive center, but are weak structures.